Drywall finishing system

ABSTRACT

A drywall finishing system for finishing 1) normal inside and outside corners of any angle, 2) stub wall or closet corners, 3) window wrap corners, and 4) L-metal for window sills and areas where drywall ends against some other surface like brick. The finishing system comprises a preformed trim piece comprising a semi-rigid member that is relatively thick in the center and tapers laterally to a thin edge. A layer of paper is bonded to the inside surface of the semi-rigid member for receiving joint compound to continuously bond the trim piece to the dry wall; this paper layer can optionally have a layer of adhesive material on its outer surface. A layer of finishing material is bonded to the exterior surface of the semi-rigid member.

This application is a continuation of application Ser. No. 12/959,202filed Dec. 2, 2010 which was a continuation of application Ser. No.11/176,952 filed Jul. 7, 2005, now abandoned which was a continuation ofapplication Ser. No. 10/200,478 filed Jul. 20, 2002, now abandoned,which was a continuation of application Ser. No. 09/715,614 filed Nov.17, 2002, now abandoned, which was a continuation of application Ser.No. 09/191,861 filed Nov. 12, 1998, now U.S. Pat. No. 6,148,573 issuedNov. 21, 2000. Application Ser. No. 09/191,861 was acontinuation-in-part of application Ser. No. 08/832,470 filed Apr. 2,1997, now abandoned, and was also a continuation-in-part of applicationSer. No. 08/718,137 filed Sep. 18, 1996, now abandoned. Both applicationSer. Nos. 08/832,470 and 08/718,137 were continuations-in-part of asingle parent application Ser. No. 08/544,339 filed Oct. 17, 1995, nowabandoned.

BACKGROUND

1. Field of the Invention

This invention relates generally to the field drywall construction andmore particularly to a system of exterior and interior drywall seams andcorners that greatly reduces the amount of time, labor and materialrequired to finish a modem structure.

2. Description of Related Art

The use of gypsum drywall board in modern construction is well known.Manufactured drywall sheets are nailed to studs to form interior wallsand ceilings. Before these sheets can be painted or textured, the jointsmust be taped and sealed with joint sealing compound (drywall mud).Drywall tape is a porous fibrous material, usually paper, which isdesigned to permanently bond with drywall mud.

Taping also (known as stringing) is a tedious process. First, mud andtape must be applied by hand or dispensed with a tool known as abazooka. The worker rolls and glazes the tape while the mud is wet. Asthe tape strings out, it has a tendency to pull in the direction ofmotion. After the tape is applied, it is coated with additional mud andthe edges are feathered with a wide blade drywall knife to form a smoothtransition between the seam and the wall. The mud is then allowed todry, typically overnight. Next, the seam is sanded, recoated with mud,dried and sanded again. The process is repeated if necessary until asmooth seam is produced.

Corners present a special problem. Inside corners are finished usingdrywall tape in much the same manner as flat joints. Outside corners aretypically finished with corner beads.

Corner beads are either sharp edged or rounded nose, also known as“bullnose.” These are used on exterior corners at windows and otheropenings. To use a standard corner bead, it first must be cut from astandard length of 8 feet or 10 feet. The bead is nailed into positionusing short nails approximately every foot. The worker must: 1) keep thebead plumb or level, and 2) keep the bead at the proper angle to preventslipping too far to one side or the other. If this latter conditionoccurs, a “shiner”, as it is called in the trade, results. This is wherethe bead is too far toward one side of the corner making the other sideflange hard to coat.

Once the bead is installed, the worker must “first coat” the bead. Thismeans to coat it with mud for the first time. This is very laborintensive, and it uses a large amount of mud. The bead projectsoutwardly from the corner. Accordingly, when first coat is applied awedge of mud is formed which is thickest at the bead and tapers out tomeet the wall. After the first coat, the mud is allowed to dry. Dryingtakes about a day.

After the “first coat” is dry throughout the building, the worker has tosand this first coat of mud and clean all the metal edges. This isespecially difficult with bullnose bead. After the “first coat” issanded, the worker proceeds to “second coat” the bead repeating theentire process again and waiting another day to dry. The worker finallymust again sand the bead carefully looking for imperfections, andtouching these up. At this point, the bead is ready for texture orpaint. The entire process uses considerable mud, and is very laborintensive, especially the sanding. In terms of total construction time,it requires two to three days to complete all the corners of a typicalresidence.

An alternative to fixed corner beads, especially for corners that do notmeet at 90 degrees is a product known as “flex bead.” Flex bead consistsof two thin strips of metal bonded to a two inch paper tape. To use“flex bead”, a worker first spreads all-purpose mud along the wallboardon both sides of the angle. A length of “flex bead” is folded by hand tocreate a crease. The bead is then installed in the angle. This requiresa good eye for straight lines since the “flex bead” will not make astraight line by itself. The worker must move the bead around to thebest of his abilities to set it as straight as possible. On manyoccasions, the worker will end up with a line that is not straight; thiscondition is called “snaking”.

Once the “flex bead” is installed and dry, the first coat procedure isstarted. Most journeymen only coat one side of the angle at a time. Ifone tries to coat both sides at the same time, the mud flops over to theother side, and the knife digs a line into the mud on the other side ofthe angle. Therefore, the following process is usually used: 1) Apply afirst coat of mud to one side and wait until it is dry; 2) Apply a firstcoat of mud to the other side and wait until it is dry; 3) Sand bothsides and clean at the crease; 4) Apply a second coat of mud to one sideand wait until it is dry; 5) Apply a second coat of mud to the otherside and wait until it is dry; 6) Sand and touch up both sides. Thisprocess is tedious, and requires considerable time while the respectivesides are drying. Accordingly, considerable drawbacks remainunsatisfied.

What is badly needed is a system for finishing drywall on the interiorof buildings that avoids the difficulties of taping, corner beads and“flex bead” while retaining the perfect finished appearance that isrequired for texturing or painting. The sanding steps should be reducedor eliminated. This system should reduce the labor to less than one dayfor a typical residence and significantly reduce the amount of mud used.

SUMMARY OF THE INVENTION

The present invention relates to a drywall finishing system forfinishing 1) inside and outside corners of any angle, 2) stub, end orcloset walls, 3) window wrap corners, and 4) L-member for window sillsand areas where a drywall ends against another surface e.g. brick. Inaddition, the system includes accessory products for each of the piecesmentioned.

The drywall finishing system of the invention in its most basic form isan elongated, preformed trim piece comprising a semi-rigid member havingtwo flanges and inner and outer surfaces. The inner surface is providedwith bonding means for continuously bonding the semi-rigid member to thedrywall. The outer surface of the finishing member is provided withfinishing means adapted to receive paint or other texture. The flangesof the semi-rigid member are tapered in a lateral direction, beingthickest at the center and tapering to a thin edge.

A first preferred embodiment is a flexible trim piece, comprising asemi-ridged member having two flanges, each of the flanges being taperedto a thin lateral edge. The semi-rigid member has a longitudinal groovebetween the flanges forming a hinge. A covering material is bonded tothe inside surface of the semi-rigid member. The covering material ispreferably drywall tape for forming a good continuous bond with drywallmud between the trim piece and the drywall. A finishing material isbonded to the exterior surface of the semi-rigid member. The finishingmaterial is preferably a fibrous material such as a paper which issuitable for directly receiving paint or other texture. The finishingmaterial may desirably extend laterally beyond the respective side edgesof the semi-rigid member forming side tabs.

To install the first embodiment of the invention, a length of preformedtrim piece is selected from stock and cut to length if not exactly theright length. A flat coat of mud is applied to both sides of a drywallcorner. The preformed piece is folded at the groove to match the corner,and placed over the mud and smoothed into place. Since the trim piece ofthe invention is preformed, the piece makes a straight line at therequired angle. Once, the piece is in place, the edges are feathered or“killed” once with a small amount of mud and a wide drywall blade orknife. At that point the corner is complete except for drying. Itrequires little or no sanding. After the mud has dried, the finishingmaterial can be directly textured or painted.

The present invention is placed on top of a coat of applied mud at thecorner. The corner can be an exterior or interior angle. No nails arerequired, since the invention pieces stick to the mud. The exteriorfinishing material is paper, plastic, or other suitable material forreceiving texture or paint. The present invention eliminates most of theintense labor associated with present methods since none of the partsneed to be coated with mud or sanded. In addition, the parts formstraight, finished lines and angles as soon as they are installed.

Additional embodiments of the invention include right angle outsidecorner trim pieces, bullnose outside corner trim pieces, stub or endwall trim pieces, U-shaped and V-shaped joint pieces, and other trim andspecialty pieces.

These advantages and other advantages of the present invention willbecome more fully apparent from the following detailed description whenread in conjunction with the accompanying drawings

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of this invention, reference shouldnow be made to the embodiments illustrated in greater detail in theaccompanying drawings and described below by way of examples of theinvention.

FIG. 1 is a cross-section through a prior art outside corner bead.

FIG. 2 is a cross-section through a prior art bullnose outside cornerbead.

FIG. 3 is a cross-section through a prior art end wall.

FIG. 4 is an end and interior perspective view of a first embodiment ofthe invention comprising a flexible corner trim piece.

FIG. 5A is a cross-section of the first embodiment of the invention.

FIG. 5B is the piece from FIG. 5A on a wall;

FIG. 5C is an installation chart.

FIG. 6 is a cross-section of the first embodiment applied to aright-angle, outside drywall corner.

FIG. 7 is a cross-section of the first embodiment applied to an acuteangle outside drywall corner.

FIG. 8 is a cross-section of the first embodiment applied to an obtuseangle, outside drywall corner.

FIG. 9 is a cross-section of the first embodiment applied to an insidedrywall corner.

FIG. 10 is a perspective view of a second embodiment of the inventioncomprising an outside right angle corner piece.

FIG. 11 is a cross-section of the second embodiment applied to anoutside drywall corner.

FIG. 12 is a perspective view of a third embodiment of the inventioncomprising an outside right angle bullnose corner piece.

FIG. 13 is a cross-section of the third embodiment of the inventionapplied to an outside corner.

FIG. 14 is a perspective view of a fourth embodiment of the inventioncomprising an end wall trim piece.

FIG. 15 is a cross-sectional view of the fourth embodiment partiallyapplied to an end stub wall.

FIG. 16 is a cross-sectional view of the fourth embodiment fully appliedto an end wall.

FIG. 17A is a perspective view of a fifth embodiment of the inventioncomprising a U-shaped joint trim piece.

FIG. 17B shows a cross-section.

FIG. 18A is a cross-sectional view of the fifth embodiment applied to aV-shaped joint.

FIG. 18B shows a cross-section.

FIGS. 19A and 19B show a sixth embodiment of the invention that forms aspecialty corner piece.

FIG. 20 shows an seventh embodiment comprising an end wall or closetspecialty piece.

FIGS. 21A and 21B show a eighth embodiment comprising a window trimpiece.

FIG. 22 shows a ninth embodiment comprising a specialty piece for windowtrim.

FIGS. 23A and 23B show a tenth embodiment comprising an L-member piece.

FIGS. 24A and 24B show an elliptical, no-coat wall patch.

FIG. 25 is a cross section of a rigid bull-nose embodiment of thepresent invention.

FIG. 26 shows a method for joining pieces of flex-trim end-to-end.

It should be noted that many of the figures show exaggerated featuressuch as the thickness of various members and materials. This isnecessary to adequately describe and point out the features andadvantages of the present invention.

DETAILED DESCRIPTION Description of Prior Art

FIGS. 1-3 illustrate prior art drywall corner finishing systems. FIG. 1shows a conventional right-angle sharp corner bead. Drywall pieces A andB join to form a corner. Corner bead C comprises bead D projectingoutwardly from the wall, and two flanges E which are nailed to thedrywall. A triangular wedge of drywall joint compound or mud F is formedbetween the drywall surfaces A and B and bead D covering flanges E. Thewedges F are formed by applying a first coat of mud over the corner beadC and adjacent portions of drywall A and B. The first coat is appliedwith a wide flat blade drywall knife. The blade rides along bead D at anangle to the wall and spaced outwardly from flanges E. This results in adeposit of a thick layer of mud over the flanges. Because the layer isthick it requires an extended drying time, typically over night.Moreover, the thick layer will tend to experience shrinkage and crackingwhile drying.

After the layer has dried, it is rough sanded. Next, a second or finishcoat of mud is applied over the first coat to fill any cracks, holes orother irregularities in the first coat. The finish coat is allowed todry. Afterwards, the finish coat is fine sanded. Occasionally a secondfinish coat is required, followed by another fine sanding. The processof finishing the corner may take two or three days. The time, labor andmaterial quantities and attendant cost required to build the corner aredirectly proportional to the volume of mud that forms wedges F.

FIG. 2 shows a conventional bullnose corner. The bullnose corner of FIG.2 differs from the corner bead of FIG. 1 primarily in the radius of thecorner member C. The reference letters A-F in FIG. 2 correspond to thesame technical features discussed in reference to FIG. 1. One differenceis that in the case of the bullnose corner two distinct ridge lines Dare formed where the mud F meets the corner bullnose piece C. There is asignificant arc of exposed bullnose between the two ridge lines. Whenfinishing a bullnose corner, excess mud is commonly deposited on thisexposed arc. It is thus necessary to sand the exposed arc to remove theexcess mud. As with the sharp corner bead, thick wedges of mud F arebuilt up on both sides of the corner member at significant labor andmaterial costs. A further problem encountered with prior art corners isthat cracks commonly form at the edge of the flange E, especially if thecorner is banged for any reason. Traditional bullnose corners also showa ridge lines D which are esthetically detracting. Cracks detract fromthe appearance of the corner.

FIG. 3 shows a conventional stub wall or closet wall piece. Again, thereference letters A-F in FIG. 3 refer to the corresponding structurepreviously discussed in reference to FIGS. 1 and 2. The end wall orcloset member suffers the same drawbacks as the bullnose corner. Indeed,there is an ever greater surface area between ridge lines D that must besanded to remove excess mud.

The primary drawbacks of the prior art are: (1) the labor and materialcosts necessary to build and finish the wedge of mud F between themember C and the drywall; (2) the significant time required to allow themud to dry between applications, i.e., two to three days; and (3) thepropensity for cracking along the edge of the flange E and the showingof ridge lines D. Each of these long standing problems in the prior artare solved by the product and method of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIGS. 4 and 5, a first embodiment of the present invention,that will be called “Ultra-Flex”, is seen generally at 10. Thisembodiment can be used for inside or outside corners. Its constructionis that of an elongated semi-rigid member 12 with an interior layer ofcovering material 14 and an exterior layer of finishing material 16laminated thereto. The semi-rigid member 12 can be plastic, metal, orother flexible, but strong material, with high impact plastic such asthat used to construct modern cola bottles being preferred. The membercan be supplied in 10 or 12 foot lengths, or any other convenientlength, or it can be supplied on a roll of 100 feet or any otherconvenient length. Running the length of the member is a groove 18. Thegroove divides the piece into two flanges 20 that can be repeatedly bentto form any angle from about 15 degrees to about 345 degrees. In thismanner, the piece can be bent to match any inside or outside corner. Theelongated semi-rigid member has a first or inside surface 22 that issplit into a left part and a right part by the groove 18. It also has asecond or exterior surface 24 that is continuous (the groove 18 does notpenetrate all the way through). The semi-rigid member is preferablylaterally tapered from a maximum thickness near the groove 18 to aminimum thickness near lateral edges 26. The maximum thickness can bebetween 10 mil and 120 mil near the groove and between 2 mil and 60 milat the edges with the thickness at the edges always being less than thethickness near the center. The preferred maximum thickness is at least54 mil, and the preferred minimum thickness is less than 10 mil.

Tapering should be distinguished from the edge bevel. The object oftapering is to form an elongated preformed wedge similar inconfiguration to the conventional wedges of drywall mud built in situ.See reference letter F in FIGS. 1-3.

Accordingly, the preformed, tapered semi-rigid member replaces the laborintensive, costly operations of conventional corner beads. A bevel onthe other hand is an abrupt edge cut that would not materially reducelabor or material costs.

FIG. 5 is a cross-section of the “Ultra-flex” piece. The groove 18 ispreferably V-shaped, and the overall cross section (without the groove)is triangular with tapering that can start anywhere. The semi-rigidmember 12 gives the piece strength and support. The groove 18 forms ahinge at 28 which allows the piece to be repeatedly bent to any anglebetween about 15 and 345 degrees. If the material chosen for thesemi-rigid member is high-impact plastic, bending does not fatigue thehinge, and the member can be bent any number of times without breaking.Also, the member in that manner is extremely strong and can resistnumerous direct blows to its surface and hinge 28 without any damage.

The groove 18 separates the first surface 22 of the piece into a lefthalf and a right half. These two halves do not have to be the samewidth. In fact, one of the halves can be considerably wider than theother to form an L-trim member or similar type member if desired. Thefirst surface 22 of the semi-rigid member 12 can be covered by twostrips of covering material 14 firmly bonded to the semi-rigid member12. This covering material can be paper similar to that used on drywall,or joint tape paper, or other suitable material adapted for forming acontinuous bond to drywall with mud. It should be noted that adhesiveother than drywall mud could be used to attach the present invention todrywall; however, the preferred method is to use only drywall mud. Alsoit should be noted that the groove 18 can normally be formed duringextrusion of the semi-rigid member 12; however, it is also possible toform it using a scoring tool or a set of male/female scoring tools. Thepreferred method is to extrude the semi-rigid member 12 and use anextrusion die to form the groove 18.

The second surface 24 of the semi-rigid member can be covered by a stripof finishing material 16 also firmly bonded to the semi-rigid member 12.The finishing material preferably extends laterally beyond the edges ofthe semi-rigid member forming side tabs 30. The side tabs 30 are adaptedto be adhered to the drywall. The finishing material can be cup stockpaper having an outer surface that can directly receive paint ortexture. It can be any other material that can directly receive paint ortexture without the need of sanding or mud.

Both the covering material and finishing material layers are bonded tothe semi-rigid member. By bonded, what is meant is any process thatfirmly attaches the material to the member. Glue could be used, but itis preferable to extrude the entire piece with the semi-rigid memberbeing high impact plastic. Here, the plastic with the groove and bothpaper layers are laminated together with the plastic being hot melted tothe paper layers for a permanent bond. The groove 18 can be made with anextrusion die.

The first embodiment shown in FIGS. 4 and 5 is only one way of makingthis type of piece. The piece can be made with any number of grooves toform flexible specialty pieces. In particular, it can be constructedwith two grooves to form a stub or end wall piece. Also, the groove canbe of other suitable cross sections as required. One great advantage ofthis embodiment is that the groove allows the piece to be bent to formperfect corners. There is no “snaking” of the corner line, even onuneven walls or construction. Also, since this type of piece can be usedat any angle, it can be used anywhere in a modem building.

It is also possible to make the first embodiment with the semi-rigidmember very thin to be extra-flexible for use primarily in interiorcorners with angles less than or equal to 90 degrees. This embodimentmay have a constant, rather than tapered, cross section. Pieces forinterior angles greater than 90 degrees must be much stronger since ithas been discovered that if a flexible piece is used for such an angle,the shrinkage of the mud coupled with building movement causes theentire piece to deform and shift leading to unacceptable work.

The “Ultra-Flex” and other pieces can be supplied on rolls as well as inprecut lengths. In order that long pieces of the material can be puttogether end-to-end, it is possible in manufacture to stampapproximately 1 inch on the back of the material on one end of theproduct with a half cut enabling the user to peel off the plastic andback paper (or other fibrous material) leaving only the front paper (orother fibrous material). In this way pieces can be joined end-to-endseamlessly. This aspect of the invention will be further discussed inreference to FIG. 24.

FIGS. 6-9 illustrate the first embodiment of the trim piece of theinvention applied to a variety of different drywall corners. FIG. 6shows a right angle outside corner made with the trim piece of theinvention. The trim piece 10 is applied to drywall 30 with conventionaldrywall compound or mud as discussed in greater detail below. The edgesbetween the piece 10 and drywall 32 is feathered or “killed” with mud 34to provide a smooth surface. Note, however, that there is a markedreduction in the amount of mud utilized as compared to the prior artcorner FIG. 1. FIGS. 7, 8 and 9 show the same features and benefits withrespect to acute, obtuse and inside corners, respectively.

A method of installing the first embodiment of the invention is asfollows. A worker first applies drywall mud to both side walls of thecorner to be finished. The pre-formed trim piece is cut to length andplaced in the corner against the wet mud. The piece is positioned forfinal appearance and pressed into place; then, the excess mud can bewiped or rolled out, and finally the edges are “killed” by applying asmall amount of finishing mud to the edges and smoothing them with awide blade knife so that they merge into the surrounding drywall. Thereis no further finishing. When the mud dries, the corner is ready forpainting or texturing. This represents a considerable savings in timeand money over existing methods.

A second embodiment is illustrated in FIGS. 10 and 11 comprising afixed, right angle outside corner piece. The second embodiment trimpiece can be constructed using the techniques discussed in relation tothe first embodiment, but without the groove. The piece is made with anextruded fixed angle of near 89 degrees or any other desired angle. Theangle is somewhat less than 90 degrees so the trim piece will slightlygrip the dry wall and applied mud. This piece is ready to receive paintor texture and is installed by simply placing it on wet mud, aligning itcorrectly, pressing it into place, wiping or rolling out the excess mud,and then killing or feathering the edges with a small amount of mud.Such a piece takes the place of current exterior drywall corner pieces(see FIG. 1) leading to a perfectly sculptured preformed corner withoutthe extreme labor associated with building up mud, sanding, andfinishing conventional corners.

The right angle corner trim piece 50 comprises an elongated semi-rigidmember 52 with an interior layer of covering material 54 and an exteriorlayer of finishing material 56. The semi-rigid member 52 is preformedwith a permanent right angle between flanges 60. The flanges are eachlaterally tapered from a maximum thickness at the corner 58 to a minimumthickness near lateral edges 66. Tapering can start at the corner or itcan start a distance away from the corner 58.

The first or inside surface of semi-rigid member 52 is covered with twostrips of covering material 54 firmly bonded to the semi-rigid member asdescribed in reference to the first embodiment. Similarly, the second oroutside surface of semi-rigid member is covered with a strip offinishing material 56 also firmly bonded to the semi-rigid member. Asdescribed in reference to the first embodiment, the finishing materialextends laterally beyond the edges of the semi-rigid member forming sidetabs 70.

FIG. 11 shows the trim piece of the second embodiment installed on adrywall outside corner. Drywall sheets 72 form a conventional rightangle, outside corner. The trim piece 50 is continuously adhered to thedrywall with mud as described above. The edges between the trim piece 50and drywall 72 are feathered with a relatively small quantity of mud 74to provide a smooth surface. The exterior surface of the trim piece isnot coated with mud, however, as was customary with prior art cornerbeads. Compare FIG. 11 to FIG. 1. There is a dramatic reduction in theamount of drywall mud utilized—up to 75% less mud. The reduction in thequantity of mud directly translates to corresponding dramatic reductionsin the amount of drying time and labor.

FIGS. 12 and 13 illustrate a third embodiment of the trim piece 110 ofthe invention comprising a rounded or bullnose right angle outsidecorner piece. Trim piece 110, as with the first two embodiments,comprises a semi-rigid member 112 with an interior layer of coveringmaterial 114 and an exterior layer of finishing material 116 laminatedthereto. The semi-rigid member 112 can be preformed with a permanent88-90° radius 118. The exact angle is not critical and can be preformedto other angles encountered in the field such as 135 degrees, or anyother angle. The preferred material is high impact plastic, with auniform thickness of 0.057 inches in the radius. The radius is a truecircular arc—there are no ridges or beads. The semi-rigid member 112further comprises flanges 120 that can taper laterally from a maximumthickness at radius 118 to a minimum thickness near lateral edges 126,or can taper laterally from maximum thickness at a point slightly awayfrom the radius 118 to a minimum thickness near lateral edges 126.

As with the first two embodiments, strips of covering material 114 arebonded to the first or interior surface of the semi-rigid member andfinishing material 116 is bonded to the second or exterior surface. Thefinishing material extends laterally from the semi-rigid member formingside tabs 130.

FIG. 13 shows trim piece 110 installed on a right angle drywall outsidecorner. Trim piece 110 is continuously bonded to drywall 132 withconventional drywall mud. The edges 134 between the side tabs anddrywall surface are feathered with a small amount of mud. The exteriorsurface of trim piece 110 is substantially free from mud and suitablefor directly receiving paint or texture. Because the trim piece 112 is atrue, preformed radius, there are no ridge lines as are common in theprior art. Compare FIG. 13 to FIG. 2.

FIGS. 14-16 illustrate a fourth embodiment of the trim piece 150 of theinvention. Trim piece 150 is specifically adapted for end walls, such ascloset openings. A normal closet opening having a top wall and two sidewalls will require six lengths of conventional corner bead and ninesurfaces to coat with a minimum of two coats of mud. The trim piece 150is used to finish a closet opening in a single operation.

Trim piece 150 comprises an elongated semi-rigid member 152 having aninterior layer of covering material 154 and an exterior layer offinishing material 156 laminated thereto. Trim piece 150 is preformedwith flanges 160, and a center portion 161 between the flanges. Theflanges are each laterally tapered from a maximum thickness adjacentcenter portion 161 to a minimum thickness near lateral edges 166. Trimpiece 150 is preformed with a permanent right angle at 157 between oneflange 160 and center portion 161. Running the length of the member is agroove 158 between center portion 161 and the other flange 160. Thegroove 158 forms a hinge so that the other flange may be rotatedrelative to the center portion. In addition, there can be two groovesinstead of a groove and a right angle 157. The right angle 157 can bereplaced by the second groove. In this case, the piece can be made flat.

The center piece 161 can be different widths (distance between theflanges 160) depending on the construction. In the case of a 3½ inchstud and two ½ sheets of drywall, the center piece would be around 4½inches wide. In the case of the same stud with two ⅝ sheets of drywall,the width would be around 4¾ inches. Different versions of this piececan be made for typical construction situations; specialized versionscan be made for any situation. The width of the flanges 160 can bebetween 1 inche and 12 inches, with about 2¼ inches being preferred. Thethickness of the center piece 161 can be from around 20 thousands of aninch to around ½ inch to form a finished wall. This thickness is notcritical to the invention, and many other thickness are possible.

FIG. 15 shows trim piece 150 partially installed on an end wall. The endwall is formed by a stud 171 and drywall sheets 172. Trim piece 150 isinstalled by first applying mud continuously to both the sides and endof the end wall. The preformed corner portion of the trim piece is thenpressed firmly in place. The edge between the fixed flange 160 and thedrywall is feathered. Next, as shown in FIG. 16, the other flange 160 isrotated about hinge 158 and pressed into the wet mud to complete thecorner. The remaining edge is feathered. Thereby, the end wall isfinished in a single operation.

FIGS. 17 and 18 illustrate a fifth embodiment of the trim piece 210invention adapted for U-shaped or V-shaped, recessed expansion joints.Expansion joints are used in many commercial buildings such as airports,hotels and shopping malls where there is a wall space large enough toraise concerns of cracking due to expansion and contraction. TheU-shaped or V-shaped expansion joint commonly comprises a ½ inch squarerecess between two sheets of dry wall 232 as seen in FIG. 18. The fifthembodiment trim piece 210 comprises a semi-rigid member 212 withlaminated covering material 214 and finishing material 216. Thesemi-rigid member has center portion 212 of substantially uniformthickness, between tapered flanges 220. The inside surface of thesemi-rigid member is provided with four parallel grooves 218, eachoperating as a hinge. Thereby, the trim piece may be flexed at thegrooves to conform to the expansion joint recess as shown in FIG. 18.The U-shaped or V-shaped expansion joint of FIGS. 17 and 18 can besupplied either preformed as “sticks” pre-cut to standard lengths or onrolls of around 100 feet or other convenient length.

FIGS. 19A and 19B depict a sixth embodiment that forms a specialty piece310 for corners that can be used in conjunction with the trim pieces ofembodiments one through five. The piece of 310 is shaped to be usedwhere two right angle walls join a ceiling at an opening. Trim piece 310preferably comprise a semi-rigid member 312 with laminated coveringmaterial 314 and finishing material 316 as described above, with twoadded flaps 345 and 346 of finishing material. An outer flat flap 345fits the higher wall and extends over the opening. A second flat flap346 runs the vertical wall forming the opening and also along the top ofthe inside of the opening. The angle between the wall parts 347 and theangle between the top of the opening and the wall 348 should be around89 degrees for a right angle system; however, parts can be manufacturedwith any angles for special requirements or special construction angles.Trim piece 310 can be any length; however it is preferably around 7inches along the short sides, and around 10 inches along the longersides. The exterior corners can be straight edged as shown or bullnose(as in FIGS. 12 and 13) or other shape.

FIG. 20 shows a seventh embodiment comprising a specialty piece 350 toaccompany the end wall piece of FIGS. 14-16. This trim piece is usedwhere an end or closet wall meets a ceiling. The piece 350 simplycontinues the previous piece through the wall ceiling transition. It canbe seen from FIG. 20, the flanges 360 continue the design around thetransition. The center portion 161 of FIG. 14 is made to have two parts361 at a right angle. Its dimensions are similar to those of theembodiment of FIGS. 14-16. This piece can be made entirely from plastic,paper, cardboard or any other suitable material, or its construction canbe the same as the piece of FIGS. 14-16. The center portion 361 shouldhave thickness to match that of the center portion of FIGS. 14-16 whichit transitions from. As with other embodiments of the present invention,the outside corner can be sharp edged or bullnose or any other specialtyshape. The outside corners 363 of the trim piece do not have to besquare as shown in FIG. 3, but may be rounded to make them easier tofeather. While the piece can be any dimensions, the preferred size isaround 4 inches on the bases, around 2½ inches in the corners, andaround 4 to 10 inches on the long sides 360. The width of centerportions 361 can vary as is the case with trim pieces illustrated inFIGS. 14-16, for different types of construction.

FIGS. 21A and 21B show a window trim piece 410 of the present invention.This piece is used to provide a transition from wall drywall to awindow. This piece is similar to other embodiments with twosubstantially flat flanges 420 forming an approximate 90 degree angle orother specialty angle of any number of degrees. The actual angle 428 ischosen around 89 degrees for a right angle system for reasons previouslyexplained. Again a semi-rigid member 412 is used inside the flanges 420for rigidity. As in other embodiments, this piece can be plastic orother rigid material. It is used to give strength and shape to thepiece. One of the flanges contains a spacer 421 of the type previouslydescribed. This spacer is used to eliminate the need to wrap the openingwith drywall. The window piece is constructed so that one flange 420 isfrom around 1 to around 7 inches, with around 2¼ inches being typical.The other flange may be shorter to fit a window, with a typical widthbeing from around 1 inches to around 12 inches with 6 inches preferred.The piece can be supplied with several different sized flanges to fitdifferent construction situations. The semi-rigid member 412 ispreferably tapered for easy feathering by the worker. The support membercan be from about 5 inches on a 7 inch flange and can take a similarratio on a different sized flange. The spacer 421 can be any durablematerial, and can be around ⅜ inch thick. Other sizes are possible tomatch the needs of the construction. The length of the piece can be astandard 8 or 10 foot, or any other length dictated by the construction.

FIG. 22 shows a specialty trim piece 450 which is an embodiment of theinvention similar to that shown in FIG. 20 except that this embodimentis specially shaped to continue the window trim piece of FIG. 21. Here,there is only one side 460 at fits the window corner. A right angleextension 461 follows the shape of the window corner. The flanges 460are preferably tapered to a thin outer edge 466 to make featheringeasier. The corner 457 can be sharp edged as shown or bullnosed or anyother shape. The exterior angles for right angle construction are around89 degrees as in the previously described embodiments.

FIGS. 23A and 23B show a L-member embodiment 510 of the presentinvention. This piece is used under window sills, or wherever drywallabruptly ends such as an interface with brick. It is constructed likethe previously described embodiments. Even though the piece is beingreferred to as an L-metal or L-trim, this does not imply that any actualmetal is used in its construction. There is a wide flange 520 and anarrow flange 521. The narrow flange can be from around ¼ inch togreater than 1 inch. The wide flange can be from 1 inch to over 6inches. Again the length of the piece can be the standard 8 or 10 foot,or any length dictated by the construction. The semi-rigid member 512 isvery similar to the support members of the previously describedembodiments. The finishing material 516 can be paper; however, thepreferred method for this piece is to use paper covered plastic forshape and strength. As before, the outside corner 528 can be straight,bullnose, or other shape.

FIGS. 24A and 24B show an elliptical, no-coat wall patch. This featureis an embodiment of the present invention for patching holes in drywallboard. The semi-rigid member 502 is very similar to the support membersof the previously described embodiments. The piece is tapered 501 forfeathering and finishing as previously described in other embodiments.The back 503 is made of a fibrous material similar to the paper used indrywall tape, while the outer exposed surface 500 is made of a fibrousmaterial suitable for directly receiving paint or texture as in otherdescribed embodiments. As with other embodiments, the finished or outerexposed surface 500 overlaps the piece for feathering.

FIG. 25 is a cross section of a rigid bull-nose embodiment of thepresent invention. This embodiment is similar to bull-nose embodimentspreviously described with a curved section 506 and a tapered flange 504.However, this embodiment contains a portion of the cross section 505that is of constant thickness and straight for around ½ inch from theend of the taper until the curve begins. This feature prevents drywallmud from going into the curved or radius portion 506.

FIG. 26 shows a method for joining pieces of flex-trim end-to-end. Theunfinished surface of the piece 503 is stamped laterally 507 across itswidth. This stamp 507 partially penetrates into the semi-rigid supportmember 502. This stamp allows part of the non-finishing material 503 andthe semi-rigid member 502 to be removed for end-to-end joining. Thenon-finishing material and semi-rigid material is simply removed and thepieces are butted. The resulting seam can easily be finished with asmall amount of drywall mud.

While the preferred embodiments of the present invention have been shownand described, it is to be understood that various modifications andchanges could be made thereto without departing from the scope of theappended claims.

What is claimed is:
 1. A flexible drywall trim piece having width andlength comprising: a continuously extruded semi-rigid elongated plasticmember having an approximately right angle bend at approximatelyone-third of said width and an end-to-end hinge at approximatelytwo-thirds of said width, said bend together with said hinge defining afixed flange portion, a fixed center region, and a hinged flangeportion; said hinged flange repeatably adjustable about said hingewithout substantially fatiguing said hinge to a plurality of anglesbetween approximately 15 degrees to approximately 340 degrees, saidangles measured between said fixed center region and said hinged flange;said elongated plastic member having two outside end-to-end edges, saidfixed flange and said hinged flange being tapered toward said outsideedges; top and bottom paper layers substantially covering said elongatedplastic member; an adhesive layer on an exterior surface of one of saidpaper layers.
 2. The drywall trim piece of claim 1 wherein saidelongated plastic member is high-impact plastic.
 3. The drywall trimpiece of claim 1 wherein at least one of said paper layers is cup stockpaper.